Stents can generally be thought of as medical devices that support or keep open vessels, ducts, or other lumens in the body. Many stents are used to relieve an occlusion in blood vessels such as coronary arteries, veins, etc. However, stents may also be used in the intestines, the esophagus, urethra, biliary ducts, and the like.
In vascular stents, the stent is often designed to be flexible to allow the stent to be inserted into the vascular system and guided to the appropriate location. Typically, this is done using suitable guide wires, catheters, and the like. Once in position, the stent is designed to be opened and held in position in order to facilitate unobstructed flow through the vessel. Stents may be opened in a number of ways such as using a balloon catheter. The need for flexibility may vary according to the application within the body.
Stents that are left in place over a long period of time may cause problems. For example, the stent may cause weakening of the vessel wall which may result in formation of a thrombus, aneurysm, or the like. In addition, endothelial tissue may cover the stent and/or prevent treatment of restenosis. Accordingly, it would be desirable to provide a composite stent that is bioabsorbable and/or biodegradable to reduce the risk that is otherwise associated with permanent stents.